• Journal of Korea Game Society
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• v.8 no.2
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• pp.57-68
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• 2008

Texture Mapping is a technique for adding realism to an image in 3D graphics Chip. Bilinear filtering mode of this technique needs accesses of 4 texels to process one pixel. In this paper we analyzed the access pattern of texture, and proposed the high performance texture cache which can access 4 texels simultaneously. We evaluated using simulation results of 3D game(Quake 3, Unreal Tournament 2004). Simulation results show that proposed texture cache has high performance on the case where physical size is less then or equal 8KBytes.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.177-183
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• 2012

Calcific tendinitis of hand and foot is rare and frequently misdiagnosed because of its rare incidence and its similar clinical presentation to other conditions such as infection. Awareness of the typical location as well as familiarity with the imaging findings is essential for making a correct diagnosis of this rare condition. We report four cases of calcific tendinitis of hand and foot, occurring in the flexor hallucis brevis, abductor digiti minimi, and abductor pollicis brevis.

• Imaging Science in Dentistry
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• v.38 no.2
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• pp.117-120
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• 2008

The odontogenic keratocyst (OKC) is a developmental odontogenic cyst typically occurring in the jaws. Since the first description of OKC was published in 1956, the lesion has been of particular interest because of its specific histopathologic features, high recurrence rate, and aggressive behavior. Recurrences most commonly arise within bone at the site of the original cyst. However, as lining cells may find their way into surrounding tissues either from implantation during surgery or from cortical perforation recurrences may arise at a distance from the original cyst. Here, we report a rare case of recurrent OKC which was first developed in mandible and recurred within the masticatory space.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.90-94
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• 2008

1999년과 2002년 각각 Terra와 Aqua센서를 탑재하여 발사된 MODIS 위성은 36개의 분광밴드, 250m, 500m, 1km에 이르는 다양한 공간해상력 및 주.야간 각 2회의 촬영을 통하여 전 세계에서 발생되고 있는 다양한 지구환경 및 변화를 연구하는데 사용되고 있다. NASA MODIS Science Team에서는 이를 위해 44개에 이르는 표준 product를 정의하여 알고리즘 처리 결과를 웹사이트를 통해 제공하고 있다. 또한 우리나라의 경우에도 한국항공우주연구원, 기상청, 국립수산과학원등에서 MODIS자료를 직수신하여 분석 및 활용하고 있다. 본 연구에서는 이러한 MODIS 자료를 활용하여 한반도 국토모니터링을 위한 자료 획득 및 처리 시스템 설계에 대한 연구를 하고자 한다. 이를 위해 한반도 일대의 MODIS 자료를 직수신하고 있는 기관으로부터 KREONet을 이용하여 준 실시간으로 영상자료를 획득 및 저장하도록 설계하였다. 또한 자료의 분석 및 처리를 위한 관련된 MODIS 표준 product를 살펴보고 이를 분석처리 할 수 있는 시스템 구성에 대해 제시하고자 한다.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.241-254
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• 1999

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile. sensitivity. specificity and accuracy were considerably high(0.83. 0.86. 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.210-217
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• 2003

A novel characteristic value extraction method based on mathematical morphology is proposed. Morphological spatial frequency defined by morphological pattern distribution function is introduced and applied to define a new feature called ‘average height.' The average height is used to define a characteristic value which is to be used to generate an index key value for content-based image retrieval. Superiority of the method was proved for various images by experiment. Furthermore the fact that the proposed method does not need threshold to obtain binary image provides its applicability to content-based image retrieval.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.20-22
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• 2004

유기 EL(Organic Light Emitting diode : OLED)은 자체발광 소자로서 액정 디스플레이(Liquid Crystal Display)에 비해 빠른 응답속도, 넓은 시야각 등의 뛰어난 화질 표현이 가능하다. 구동 박막 트랜지스터(TFT)의 전류가 OLED의 휘도를 결정하므로, 고품질의 영상을 위해 미세한 TFT 전류 조절 능력이 매우 중요하다. 비정질 실리콘(a-Si) TFT는 그레인 구조를 갖는 다결정 실리콘(poly-Si) TFT에 비해 균일한 전기적 특성을 나타내지만, 장시간 구동에 따른 문턱전압의 열화가 발생한다. 본 논문에서는 상기의 문제점을 최소화하기 위하여 positive bias에 의한 열화를 negative bias로 어닐링하는 구동방법을 제안하였다. 본 회로는 2개의 게이트 선택 신호와 6개의 a-Si TFT로 이루어져 있다. 실험 결과를 통해 추출된 소자 parameter를 바탕으로 제안된 회로의 simulation을 수행 및 검증하였다. 본 회로는 a-Si TFT에서 발생하는 문턱전압 열화 등의 신뢰성 문제를 감소시킨다.

• Journal of Korean Institute of Fire Investigation
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• v.9 no.1
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• pp.27-34
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• 2006

2004년 2월~5월까지 대구시 달서구 00동 소재에서 연쇄방화가 발생 되어 수사를 하여 오던 중 우리경찰서에서 다방면으로 수사하여 차량화재 방화범 000를 검거 후 기소한 상태에서 공판이 진행되던 과정에서 변호인 측에서 일회용 라이터로는 차량을 착화 또는 발화의 가능성이 현저히 어렵다는 이유로 피고인의 무혐의를 주장하는 변론이 제기되어 00지방검찰청 000 담당검사의 요청에 의하여 혐의를 입증하고 검증할 수 있는 자료를 제출하고 검증자료가 없으면 본 건의 조건에 따르는 실험을 실시하고 감정결과를 제출하라는 지휘에 의거 우리경찰서 과학수사팀에서는 차량(프라이드)을 1대 구입하여 지방경찰청 과학수사팀, 국립과학수사구소 남부분소 이공학실 화재 연구실과 연계하여 차량화재 실험을 실시하고 실험과정 및 발화 행태와 양상을 구체적으로 증명할 수 있는 자료를 조사연구 분석하고 국립과학수사 연구소에서는 00지방검찰청에 촬영 데이터 원본영상과 촬영물, 그리고 감정서를 작성, 실험 결과를 문서화하여 제출하여 혐의를 입증한 사례 연구로 피의자에 대한 혐의 입증시 상황이나 정황 증거보다 실체적 진실증거의 중요성을 재인식 하고자 한다.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.17-24
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• 2002

In this paper, we propose a new watermarking method using isolation of invalid blocks for image authentication. We embed messages into the high frequency band in the DCT domain because of its imperceptibility and fragility. And we were able to inspect the identity of valid blocks between error corrected original images and watermarked images through experiments. As a result, we found that the watermarked image is enough to extract binary messages. Therefore, the extra information such as the original image or watermark was not necessary in our extracting process. Experiment results show that the proposed method can be used successfully for image authentication.

• Journal of Korea Multimedia Society
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• v.17 no.10
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• pp.1205-1212
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• 2014

In this paper, we propose a high-quality stitching method of 3D multiple dental CT images. First, a weighted function is generated using the difference of two distance functions that calculate a distance from the nearest edge of an overlapped region to each position. And a blending ratio propagation function for two gradient vectors is parameterized by the difference and magnitude of gradient vectors that is also applied by the weighted function. When the blending ratio is propagated, an improved region growing scheme is proposed to decide the next position and calculate the blending intensity. The proposed method produces a high-quality stitching image. Our method removes the seam artifact caused by the mean intensity difference between images and vignetting effect. And it removes double edges caused by local misalignment. Experimental results showed that the proposed method produced high-quality stitching images for ten patients. Our stitching method could be usefully applied into the stitching of 3D or 2D multiple images.